Figure 2

Figure 2

Evolution and diversification of RPRM genes in vertebrates. (A) During the diversification of vertebrates RPRM genes were differentially retained, as not all RPRM genes are present in all main groups of vertebrates. Thus, RPRM and RPRML genes were retained in all main groups of jawed vertebrates (gnathostomes), whereas RPRM3 was only retained in four distantly related groups: cartilaginous fish (e.g., sharks, skates, and rays), holostean fish (e.g., bowfish and gars), teleost fish (e.g., zebrafish) and coelacanths. In the group that includes lampreys and hagfish, two RPRM genes have been identified, however, phylogenetic and synteny analyses have failed in defining orthology. (B) Schematic representation of the evolution of the RPRM gene family in teleost fish. On the left, the RPRM gene family diversified as a product of the two rounds of whole-genome duplication occurred in the vertebrate ancestor, as well as, a teleost-specific whole genome duplication. On the left, the expression territories of the three RPRM gene lineages present in teleost fish.